Collar attachment



FIG. 1 is a front perspective view of a collar attachment;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top side view thereof;

FIG. 7 is a bottom side view thereof; and,

FIG. 8 is a back perspective view thereof.

Note that any broken line illustration of environmental structure in the drawing is not part of the design sought to be patented. 

CLAIM The ornamental design for a collar attachment, as shown and described. 